吴越1a, 钱付平1a, 于灵涛1a, 李明月1b, 黄乃金2, 吴昊2, 郑志敏1a
1.安徽工业大学 a.能源与环境学院, b. 建筑工程学院, 安徽 马鞍山 243032;
2.安徽威达环保科技股份有限公司, 安徽 合肥 230601
引用格式:
吴越, 钱付平, 于灵涛, 等. 基于CFD-DEM的水泥窑SCR脱硝催化剂表面磨损研究[J]. 中国粉体技术, 2025, 31(5): 1-14.
WU Yue, QIAN Fuping, YU Lingtao, et al. Study on surface wear of cement kiln SCR denitrification catalyst based on CFD-DEM[J]. China Powder Science and Technology, 2025, 31(5): 1-14.
DOI:10.13732/j.issn.1008-5548.2025.05.014
收稿日期: 2024-07-04, 修回日期: 2024-09-30,上线日期: 2025-05-06
基金项目: 国家自然科学基金项目, 编号: 52176148; 安徽省重点研究与开发计划项目, 编号: 202104i07020016。
第一作者简介: 吴越(1999—),男,硕士生,研究方向为大气污染物防治。E-mail: 1253942173@qq.com。
通信作者简介: 钱付平(1974—),男,教授,博士生导师,研究方向为通风除尘系统及设备优化研究。E-mail: fpingqian@ahut.edu.cn。
摘要: 【目的】 为了研究水泥窑选择性催化还原(selective catalytic reduction, SCR)催化剂表面的磨损,分析不同条件下催化剂表面的磨损情况,以实现优化方案。【方法】 采用计算流体力学(computational fluid dynamics, CFD)与离散元法(discrete element method, DEM)的耦合方法对水泥窑SCR催化剂表面的磨损进行研究,以水泥窑SCR催化剂表面为研究对象,在验证建立的数值仿真模型的基础上,对不同烟气进口风速、 烟气入射角和粒径对催化剂表面磨损的影响进行仿真实验。【结果】 随着烟气进口风速的增加,壁面初始磨损量的均值也相应增大,并且达到稳定状态后的均值磨损量亦更高。烟气入射角度增大时,相同时间内的磨损侵蚀面积会逐渐减小。粒径越小,相同时间内的磨损均值和标准偏差均较小,催化剂表面的磨损分布更加均匀。当烟气进口风速为2、 3、 4、 5 m/s时,催化剂表面磨损均值达到稳定时分别为1.12×10-7、 1.32×10-7、2.52×10-7、 3.78×10-7 mm。约10 s后,催化剂表面磨损量的标准偏差达到最大,烟气进口风速分别为2、 3、 4、 5 m/s时催化剂表面磨损量的最大值为1.82×10-8、 2.41×10-8、 2.46×10-8、 2.52×10-8 mm。 【结论】 在催化剂表面,磨损量的标准偏差随时间变化呈现先增大后减小的趋势。同时,颗粒间的扰动导致催化剂表面的最大磨损量也经历了先增大后减小的过程。
关键词: 计算流体力学与离散元法耦合; 水泥窑SCR脱硝反应器; 磨损模型; 催化剂
Abstract
Objective This study investigates the surface wear on selective catalytic reduction (SCR) catalysts in cement kilns under various conditions to determine optimized solutions for reducing wear. It aims to identify key factors affecting catalyst surface wear and proposes optimized measures to reduce wear and extend the catalyst’s service life.
Methods A coupled approach using computational fluid dynamics (CFD) and the discrete element method (DEM) was applied to simulate wear on the cement kiln SCR catalyst surface. The accuracy of the numerical simulation model was validated using experimental data to ensure that the model could accurately reflect actual operating conditions. After validation, simulations were conducted to investigate the effects of different inlet velocities, incidence angles, and particle sizes on catalyst surface wear. The study analyzed the flow characteristics and impact mechanisms of particles at various inlet velocities and explored how changes in incidence angles affected wear distribution patterns. Additionally, the study investigated the movement trajectories of particles with different sizes and their impact on the amount and uniformity of wear distribution.
Results and Discussion As inlet velocity increased, both the average initial wear and the mean steady-state wear on the catalyst surface increased due to the higher kinetic energy generated from the impacting particles. Larger incidence angles reduced the contact area between particles and the surface, leading to decreased wear. Smaller particles resulted in lower average wear and standard deviation with a more uniform wear distribution, extending the catalyst’s service life. The experimental data showed that at inlet velocities of 2, 3, 4, and 5 m/s, the mean wear on the catalyst surface stabilized at 1.12×10-7, 1.32×10-7, 2.52×10-7, and 3.78×10-7 mm, respectively. Approximately 10 seconds later, the standard deviation of wear peaked, suggesting that the wear pattern stabilized at this point. At inlet velocities of 2, 3, 4, and 5 m/s, the maximum standard deviation values were 1.82×10-8, 2.41×10-8, 2.46×10-8, and 2.52×10-8 mm, respectively. This findings indicated that higher velocities caused greater wear and variability in wear distribution, likely due to the complex dynamic processes of high-velocity particle impacting on catalyst surface.
Conclusion The standard deviation of wear on the catalyst surface initially increases and then decreases over time, indicating high variability in the early stages of wear, possibly due to random particle impacts. However, as the system gradually stabilizes, wear variability decreases. Similarly, the maximum wear amount initially increases and then declines, likely due to the chaotic movement of particles generating significant impact energy in the early stages. Then as the system stabilizes, the movement also subsides. Furthermore, the study reveals that smaller particles tend to cause more variability in surface wear, while larger particles have a more pronounced impact on the maximum wear. These findings are crucial for understanding catalyst surface wear mechanisms and provide valuable insights for catalyst material selection and operational strategies to mitigate wear in practical applications.
Keywords: CFD-DEM; SCR denitrification; wear prediction model; catalyst
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